Confessions of a Recovering Thickie

[Hohn]

I have been poring over the UOA section looking at every UOA I can find. It sure seems to me that if you plotted wear metal rate per 1000 miles against viscosity grade, you'd have incredibly weak correlation. The R-square has to be under 10%. There are some outlier datapoints, but within the realm of modern fuel-injected gasoline cars with more than ~40k miles on them, you will see about 1ppm/1k miles of iron, which is the primary wear metal.

You run supertech or Kirkland? You'll see about 1ppm/1k miles.
HPL or Ravenol? You'll see about 1ppm/1k miles.

If you are a fan of thin oils and run 0w20, you'll see about 1ppm/1k miles of iron.
If you are a fan of thick oils and run 5w40, you'll see about 1ppm/1k miles of iron.


If you have over 2ppm/1k miles of iron, you are a BITOG outlier.

I'm forced to confess the reality that while I prefer heavier oils with low to no VII content (SAE 40, yeah baby!), there's no evidence in our UOAs that says you are significantly extending engine life vs some thinner oil that is also sufficiently protective.

Sufficient is sufficient. Being more sufficiently thick doesn't change anything but burn more fuel. Think of it this way: what can you do with a net worth of $100 billion that you cannot do with a net worth of $20 billion? Nothing, really. In both cases you are crazy rich. The fact that one is 5x the other amounts to nothing, really.

I think that's what's sort of at work here. I can, under duress of data, confess that my preference for thicker oil is emotional, not intellectual.

 

[CarlB]

Likely the average driver isn't driving hard enough / hot enough to require a thick viscosity. There isn't one answer, and it's why there is a large variety of choices depending on application.

 

[buster]

I agree. The data shows what GM and Toyota R&D have said for years - viscosity is just one variable. And most engines can run on multiple grades. An engine's B10 rating is unlikely to be impacted by oil grade under most driving conditions (racing excluded).

Viscosity is obviously important, but engines can run on a wide range of viscosities with no issue at all showing identical wear rates. The low viscosity oils today are at the lower limit threshold (HT/HS 2.3-2.6).

I think a greater problem we see is not from viscosity at all, it's from carbon plugging up the rings. That's why VRP is such a great product (sorry I had to mention it lol).

We don't see engines wearing out or failing on this site, but we DO see engines consuming oil over time.

Also from Toyota R&D:

"It is also important to note that, contrary to what many take for granted, higher viscosity in and of itself does not translate into better engine protection. Extensive testing has shown the opposite to be in fact true. As long as a lower-viscosity oil is formulated to resist evaporation and provide high film strength, this lighter oil will actually deliver more complete protection to the engine parts, since its more rapid circulation delivers both better lubrication per se, and far better cooling characteristics…a critical advantage, given that oil flow furnishes up to 30%"

 

[kschachn]

On the other hand unless fuel economy is your sole objective there’s no downside to thicker oils. Plus they give headroom for things such as fuel dilution.

And I wouldn’t put so much faith into random spectrographic analyses as your primary criteria for this faith. Measuring wear between motor oils is a test, but it’s not a collection of $30 UOA.

Finishing off your post with yet another advertisement for VRP isn’t surprising.

 

[Nessism1]

https://www.blackstone-labs.com/wp-content/uploads/2018/09/Aug-17-ENG.pdf

This is one of my favorites. In summary: motor oil is motor oil.

 

[ripcord]

I'm not even convinced that that wear metals in UOAs have any correlation to actual engine longevity.

 

[kschachn]

https://www.blackstone-labs.com/wp-content/uploads/2018/09/Aug-17-ENG.pdf

This is one of my favorites. In summary: motor oil is motor oil.

No, $30 UOA are $30 UOA and not a proper tool for this comparison.

 

[Just a civilian pilot]

I agree. The data shows what GM and Toyota R&D have said for years - viscosity is just one variable. And most engines can run on multiple grades. An engine's B10 rating is unlikely to be impacted by oil grade under most driving conditions (racing excluded).

Viscosity is obviously important, but engines can run on a wide range of viscosities with no issue at all showing identical wear rates. The low viscosity oils today are at the lower limit threshold (HT/HS 2.3-2.6).

I think a greater problem we see is not from viscosity at all, it's from carbon plugging up the rings. That's why VRP is such a great product (sorry I had to mention it lol).

We don't see engines wearing out or failing on this site, but we DO see engines consuming oil over time.

Also from Toyota R&D:

"It is also important to note that, contrary to what many take for granted, higher viscosity in and of itself does not translate into better engine protection. Extensive testing has shown the opposite to be in fact true. As long as a lower-viscosity oil is formulated to resist evaporation and provide high film strength, this lighter oil will actually deliver more complete protection to the engine parts, since its more rapid circulation delivers both better lubrication per se, and far better cooling characteristics…a critical advantage, given that oil flow furnishes up to 30%"

But I can’t help but wonder , given most people don’t ever bother to check engine oil levels , if this is why some of these engine fail, or have much shorter lifespans.

With respect to oil consumption, if I didn’t check, it would be severely low on oil with just two weeks of driving.

Engine runs fine, even with oil consumption, but that’s because I never let it get low.

 

[buster]

Engines can operate very well in that wide range of viscosity selection. But if you're looking at this site, with everything that we see, do we ever seen engines failing? No. But we do see engines over time consuming oil (if not due to just low tension ring design which no oil will help), suggesting at some point in the engines life the rings will start to build up deposits.

We've also seen pre-engine failure UOA's showing high wear metals. What's that then? No wear? UOA's do show wear metals. They may be only of a certain size, but it's still metal and it's still in the oil.

 

[buster]

I'm not even convinced that that wear metals in UOAs have any correlation to actual engine longevity.

If you're seeing an avg of 8ppm of Fe over 50k miles and it jumps to 40ppm, your engine is showing increase rate of wear. But at what rate is it a problem and will the rest of the car last long enough to see the engine actually fail?

 

[buster]

Finishing off your post with yet another advertisement for VRP isn’t surprising.

It's the only product on the market that is addressing an ACTUAL issue while everyone else debates 20 vs 50 grades for the last 25 years with no meaningful conclusion...because there isn't one. So yeah....

 

[Just a civilian pilot]

But if a person has a vehicle that starts to consume oil caused by piston ring deposits , it’s going to use a lot more oil if they let the level get too low.

The oil consumption on my car is stable but had I never checked it, it would be a lot higher than it is today ( if I only found out it was using oil because the low oil light came on between oil changes ).

Honda dealership I go to said they have customers let the oil get so low the low oil level light went off.

I am sure those owners have higher oil consumptions issues than other cars that consume oil but the owners kept an eye on it.

I NEVER see people checking their oil levels.

 

[wwillson]

I think a greater problem we see is not from viscosity at all, it's from carbon plugging up the rings. That's why VRP is such a great product (sorry I had to mention it lol).

We don't see engines wearing out or failing on this site, but we DO see engines consuming oil over time.

Modern oils basically all protect very well against wear. I use HPL because of its astounding ability to clean internals and keep them clean. Engines almost all die from stuck rings, not wear.

 

[buster]

I should have included HPL/Amsoil SS/Mobil 1 - keep rings clean. VRP is not the only product for long engine life. Mentioning it wasn't intended to make it as if VRP is the only option. It just so happens it was developed for a specific purpose for a very real issue.

 

[Just a civilian pilot]

Modern oils basically all protect very well against wear. I use HPL because of its astounding ability to clean internals and keep them clean. Engines almost all die from stuck rings, not wear.

I only used HPL and another top oil, maybe that’s why I never saw any improvement after running VRP.

Nothing left to clean?

Anyone with stuck rings will wear their engine out faster if they aren’t checking the oil and very, very few non car enthusiasts do.

They must be running low on oil a lot.

 

[buster]

But if a person has a vehicle that starts to consume oil caused by piston ring deposits , it’s going to use a lot more oil if they let the level get too low.

The oil consumption on my car is stable but had I never checked it, it would be a lot higher than it is today ( if I only found out it was using oil because the low oil light came on between oil changes ).

Honda dealership I go to said they have customers let the oil get so low the low oil level light went off.

I am sure those owners have higher oil consumptions issues than other cars that consume oil but the owners kept an eye on it.

I NEVER see people checking their oil levels.

99% of Honda's customer don't care and will go by OLM. But the more hp and turbo charged engines we see, with low viscosity oils and low tension rings, you're likely going to get some consumption. Some engines will go with no oil consumption. Maybe break-in does matter I don't know.

 

[kschachn]

It's the only product on the market that is addressing an ACTUAL issue while everyone else debates 20 vs 50 grades for the last 25 years with no meaningful conclusion...because there isn't one. So yeah....

I am using it myself at the moment. No argument there.

 

[buster]

I wonder how an OEM comes up with the B10 and whether they test a wide range of viscosities?

Take an engine that is pretty tough on oil. Take 10 of those engines and split them up 5/5 using 0w20 vs 5w30 or pick your grade. Run them all for 300k miles in a simulated test. Tear them down and see what grade did best. They're not doing that.

 

[Glenda W.]

If wear from UOA’s is your only metric for oil decisions life is simple. Even conventional oil will statistically have the same wear…

 

[Pablo]

I'm not even convinced that that wear metals in UOAs have any correlation to actual engine longevity.

This because everyone says "wear" metals. There is some metal detected in solution (not chunks) does not mean it came from what we think of as wear/contact wear